3-ALPHA-[(4-CHLOROPHENYL)PHENYLMETHOXY] TROPANE HYDROCHLORIDE

Clobenztropine,Onbio Inc.

3-CPMT is a high affinity dopamine transporter blocker.

A solution of 28.2 g (0.2 mol) of 3-tropanol is prepared in 50 ml of xylol, and to this solution is added 23.8 g (0.1 mol) of 4-chlorobenzhydryl chloride. The resultant solution is heated for 7 h at 145°-155°C, following which the mixture is cooled and filtered. The clear filtrate thus obtained is washed with 50 ml of 5% aqueous potassium carbonate solution and then with three successive 25 ml portion of water. The xylol solution is then extracted with three successive 50 ml portions of 2 N hydrochloric acid. The xylol layer is discarded and the acid extracts are combined and rendered strongly basic by the addition of 22.5% aqueous potassium hydroxide, resulting in the formation of an oily base which separates and which is then extracted with
benzol, from which the benzol is evaporated to yield crude 3-(4'- chlorobenzhydryloxy)tropane as a brown oil.
2.0 g of 3-(4'-chlorobenzhydryloxy)tropane is treated with 10 ml of 4.5 N isopropanoic acid hydrogen chloride solution, and the pasty mixture which results is diluted with approximately 30 ml of absolute ether. A solid product is formed which is separated by filtration and then washed with absolute ether. The product is then purified by dissolving it in hot isopropanol, followed by clarification with activated charcoal. Upon cooling the filtrate, the 3-(4'- chlorophenylbenzyloxy)tropane separates as a crystalline powder, melting point 215°-217°C.
In practice it is usually used as hydrochloride.

Antihistaminic